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A158284
List of pairs p, p+2 where p is prime and p and p+2 contain the same number of prime digits.
1
3, 5, 5, 7, 13, 15, 23, 25, 29, 31, 43, 45, 53, 55, 73, 75, 83, 85, 89, 91, 103, 105, 109, 111, 113, 115, 163, 165, 173, 175, 193, 195, 223, 225, 229, 231, 233, 235, 263, 265, 283, 285, 293, 295, 313, 315, 353, 355, 373, 375, 383, 385, 389, 391, 409, 411, 433
OFFSET
1,1
COMMENTS
Prime digits are 2, 3, 5 or 7.
MATHEMATICA
snpdQ[n_]:=Count[IntegerDigits[n], _?PrimeQ]==Count[IntegerDigits[n+2], _?PrimeQ]; {#, #+2}&/@Select[Prime[Range[100]], snpdQ]//Flatten (* Harvey P. Dale, Dec 04 2017 *)
CROSSREFS
Cf. A077800.
Sequence in context: A073340 A118409 A162779 * A090941 A090917 A226540
KEYWORD
nonn,base,less
AUTHOR
EXTENSIONS
(13,15) inserted, (23,25) inserted, and all other numbers replaced by R. J. Mathar, May 19 2010
Definition changed to match the terms by N. J. A. Sloane, Dec 03 2017
STATUS
approved